Gravitating Q-balls in the Affleck-Dine mechanism

TL;DR

This paper explores how gravity influences Q-balls with the Affleck-Dine potential, revealing three types of solutions depending on the parameter K, with implications for dark matter models.

Contribution

It demonstrates the existence of gravitating Q-ball solutions across different K regimes, including new solutions like boson stars and Q-matter configurations.

Findings

For K<0, gravity imposes an upper charge limit on Q-balls.

At K=0, gravity leads to mini-boson star solutions with charge bounds.

For K>0, solutions are surrounded by Q-matter and are not asymptotically flat.

Abstract

We investigate how gravity affects "Q-balls" with the Affleck-Dine potential $V_{AD}(\phi):=\frac{m^2}{2}\phi^2[ 1+K\ln (\frac{\phi}{M})^2]$. Contrary to the flat case, in which equilibrium solutions exist only if $K<0$, we find three types of gravitating solutions as follows. In the case that $K<0$, ordinary Q-ball solutions exist; there is an upper bound of the charge due to gravity. In the case that K=0, equilibrium solutions called (mini-)boson stars appear due to gravity; there is an upper bound of the charge, too. In the case that $K>0$, equilibrium solutions appear, too. In this case, these solutions are not asymptotically flat but surrounded by Q-matter. These solutions might be important in considering a dark matter scenario in the Affleck-Dine mechanism.